I'am using the [using - end using] code block where I use IDataReader. When I debug my code, I see at the end of using code block, the state of the IDatareader (isClosed=True) is always closed.

Besides this operation on .net , I also watch the connections detailly from the TOAD's Session Monitor. If I use pooling, the sessions was limited at the maximun size defined at web config ( max pool size = 10 ). It seems the pooling system is working fine. If
I don't use pooling, this time I see that every opened connection is closed after finishing its job. I seems the non-pooling system is also working fine.

My problem is, after elapsing some time, Even if everything seems going fine, I suddenly get the error message above.

But I am still getting this error. Actually I own another data acces layer written by using System.Data.OracleClient provider's functionality , is working fine. I start to get this error when I decide to use DAAB, still I want to use DAAB, so I need
to find what causes this error.

Do you think that this is an error of DAAB (EL 4.1) ,
Oracle (10 g R2), VS (Frmwk. 3.5) , Operation System (WS 2003) or our code
imlementation of DAAB ?